Differential binding of tetrodotoxin and its derivatives to voltage-sensitive sodium channel subtypes (Nav 1.1 to Nav 1.7).

The reduced binding of chiriquitoxin to Nav 1.7 was attributed to its C11-OH and/or C12-NH2 , based on reported models for the TTX-VSSC complex. Chiriquitoxin is a useful tool for probing the configuration of the TTX binding site until a crystal structure for the mammalian VSSC is solved.